Add cave shape optimizations

lua/engine.lua

@@ -37,6 +37,19 @@ local default_biome =
     , maxp = { x =  1e5, y =  1e5, z =  1e5 }
     }
 
+local cave_shape_chunk_size = 8
+
+local cluster_shape_chunks_x = 4
+local cluster_shape_chunks_y = 6
+local cluster_shape_chunks_z = 4
+
+local function reduced_pos(pos)
+    return
+        { x = math.floor(pos.x / (cave_shape_chunk_size * cluster_shape_chunks_x))
+        , y = math.floor(pos.y / (cave_shape_chunk_size * cluster_shape_chunks_y))
+        , z = math.floor(pos.z / (cave_shape_chunk_size * cluster_shape_chunks_z))
+        }
+end
 -- Convert 3d relative coordinates to an index on a flat array
 local function from_3d_to_flat(dx, dy, dz, nx, ny)
     return (nx * ny * dz) + (nx * dy) + dx + 1
@@ -252,7 +265,13 @@ local function get_connectivity_noise_params(shape_size)
     return {
         offset = 50,
         scale = 50,
-        spread = { x = factor * 250, y = factor * 100, z = factor * 250 },
+        spread =
+            reduced_pos(
+                { x = factor * 250
+                , y = factor * 100
+                , z = factor * 250
+                }
+            ),
         seed = 297948,
         octaves = 2,
         persistence = 0.2,
@@ -269,7 +288,13 @@ local function get_verticality_noise_params(shape_size)
     return {
         offset = 50,
         scale = 50,
-        spread = { x = factor * 100, y = factor * 250, z = factor * 100 },
+        spread =
+            reduced_pos(
+                { x = factor * 100
+                , y = factor * 250
+                , z = factor * 100
+                }
+            ),
         seed = 35644,
         octaves = 2,
         persistence = 0.2,
@@ -278,26 +303,30 @@ local function get_verticality_noise_params(shape_size)
     }
 end
 
--- Get the distance of each cave shape to calculate their weight.
-local function shape_distance_weight(shape_size, dx, dy)
+-- Get whether a cave shape is within distance.
+local function shape_within_distance(shape_size, dx, dy)
     local factor = math.max(math.abs(shape_size) ^ 0.5, 1)
-    local max_distance = 100 / factor
+    local max_distance = 30 / factor
 
-    if dx^2 + dy^2 > max_distance^2 then
-        return 0
-    else
-        return 1 / (dx^5 + dy^5)
+    return dx^2 + dy^2 <= max_distance^2
 end
+
+local function shape_def_distance(def, x, y)
+    local dx = math.abs(x - def.connectivity_point)
+    local dy = math.abs(y - def.verticality_point)
+
+    return dx^2 + dy^2
 end
 
 -- Get a flat map containing all flat threshold values
 local function get_threshold_flat(minp, maxp)
     local connectivity = get_flat_from_noise_params(
-        minp, maxp,
+        reduced_pos(minp), reduced_pos(maxp),
         get_connectivity_noise_params(#noordstar_caves.registered_shapes)
     )
+    
     local verticality = get_flat_from_noise_params(
-        minp, maxp,
+        reduced_pos(minp), reduced_pos(maxp),
         get_verticality_noise_params(#noordstar_caves.registered_shapes)
     )
 
@@ -305,41 +334,37 @@ local function get_threshold_flat(minp, maxp)
 
     -- Get noise for all cave shapes
     for key, def in pairs(noordstar_caves.registered_shapes) do
-        noise[key] = {
-            key = key,
-            noise = get_flat_from_shape_def(def, minp, maxp),
-            def = def
-        }
+        noise[key] = get_flat_from_shape_def(def, reduced_pos(minp), reduced_pos(maxp))
     end
 
-    -- Create the flat array
-    return Flat3dArray:from_func(minp, maxp, function(i, pos)
-        local total = 0
-        local count = 0
-
+    -- Create a (reduced) flat array
+    local reduced = Flat3dArray:from_func(
+        reduced_pos(minp), reduced_pos(maxp),
+        function(i, pos)
             local x = connectivity:get_pos(pos)
             local y = verticality:get_pos(pos)
 
-        for _, n in pairs(noise) do
-            local v = n.noise:get_pos(pos)
+            local value = 0
         
-            local dx = math.abs(x - n.def.connectivity_point)
-            local dy = math.abs(y - n.def.verticality_point)
+            for key, def in pairs(noordstar_caves.registered_shapes) do
+                local dx = math.abs(x - def.connectivity_point)
+                local dy = math.abs(y - def.verticality_point)
 
-            local w = math.abs(shape_distance_weight(
-                #noordstar_caves.registered_shapes, dx, dy
-            ))
-
-            total = total + v * w
-            count = count + w
+                if shape_within_distance(#noordstar_caves.registered_shapes, dx, dy) then
+                    value = math.max(value, noise[key]:get_pos(pos))
+                end
             end
 
-        if count <= 0 then
-            return -1000
-        else
-            return total / count
+            return value
         end
+    )
+
+    -- Create the flat array
+    local x = Flat3dArray:from_func(minp, maxp, function(i, pos)
+        return reduced:get_pos(reduced_pos(pos))
     end)
+
+    return x
 end
 
 
@@ -470,13 +495,13 @@ local function biome_def_to_content_id(def, nt, original_block)
 
     local node_air     = get_node(def.node_air, minetest.get_content_id("air"))
     local node_floor   = get_node(def.node_floor, original_block)
-    local node_stone   = original_block
+    local node_stone   = get_node(nil,           original_block)
     local node_roof    = get_node(def.node_roof, original_block)
-    local node_unknown = original_block
+    local node_unknown = get_node(nil,           original_block)
     local node_wall    = get_node(def.node_wall, original_block)
 
     if nt == node_type.unknown then
-        return node_unknown
+        return node_unknown()
     elseif nt == node_type.floor then
         return node_floor()
     elseif nt == node_type.wall then
@@ -486,7 +511,7 @@ local function biome_def_to_content_id(def, nt, original_block)
     elseif nt == node_type.content then
         return node_air()
     elseif nt == node_type.stone then
-        return node_stone
+        return node_stone()
     else
         return original_block
     end